000
AXPZ20 KNHC 212023
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
2205 UTC Thu Dec 21 2023

Tropical Weather Discussion for the eastern Pacific Ocean from
03.4S to 30N, east of 120W including the Gulf of California, and
from the Equator to 30N, between 120W and 140W. The following
information is based on satellite imagery, weather observations,
radar, and meteorological analysis.

Based on 1800 UTC surface analysis and satellite imagery
through 2000 UTC.

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: High pressure over the W Gulf 
of Mexico along with lower pressures over the tropical E Pacific 
are forcing a N gap wind event over the Gulf of Tehuantepec. Gale
conditions will continue over the Gulf of Tehuantepec tonight, 
before diminishing to strong to near-gale force through Sat.
Current peak seas are near 13 ft. 

Eastern Pacific Significant Swell event: Very large NW swell 
with seas of 12-16 ft and a 12-14 second period are continuing 
to impact the waters north of 26N between 124W-134W. An 1800 UTC 
altimeter pass verified the occurrence of these seas along 128W. 
As the swell continues to propagate southeastward, seas will 
subside below 12 ft by early Fri morning.

Please read the latest NWS High Seas Forecast issued by the 
National Hurricane Center at 
https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

The monsoon trough extends from the coast of Colombia near 07N78W
to 05N87W. The ITCZ extends from 05N87W to 09N120W to beyond 
05N140W. Scattered moderate and isolated strong convection is 
noted from 04N-07N between 97-108W, and from 03N-09N west of 
130W. 

...OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see the Special Features section for details on the 
ongoing Gulf of Tehuantepec Gale Warning. 

A cold front extends from 30N119W to 22N130W. S winds ahead of 
the front over the waters west of Baja California Norte are
moderate to fresh. Aside from the gale in the Gulf of 
Tehuantepec, a weak pressure gradient prevails across the area 
with moderate or less winds occurring this afternoon. Seas are 
3-6 ft in the Pacific, except for waters west of Baja California 
Norte where seas are 7-11 ft in NW swell. Seas in the Gulf of 
California are 1-2 ft.

For the forecast, the cold front moving over the waters west of 
Baja California this afternoon ahead of a low pressure will 
approach the U.S.-Mexico border from the west on Fri and bring
fresh to strong W to NW winds. At the extended range, high 
pressure building over the U.S. Great Basin should funnel fresh 
to strong NW winds over the Gulf of California Sun night through 
early next week. Large NW swell will propagate southeastward 
across the waters west of Baja California tonight and Fri before 
diminishing Sat. Looking ahead, another set of large NW swell 
will move into the Baja California Norte waters Sun through early
next week. 

...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, 
AND WITHIN 750 NM OF ECUADOR...

A high pressure ridge over Central America is forcing fresh to 
strong NE winds over the Gulf of Papagayo region. Seas are 8-10 
ft. Fresh N winds are also occurring over the Gulf of Panama 
with seas 6-8 ft. Elsewhere, winds are moderate or weaker. Large 
NW swell with seas to 8 ft in the Guatemala-El Salvador offshore
waters are being generated by a Gulf of Tehuantepec gale-force 
gap wind event. 

For the forecast, fresh to strong NE winds over the Gulf of 
Papagayo region should continue through Fri night. Fresh N winds
will continue over the Gulf of Panama until diminishing to 
moderate on Fri. Elsewhere, winds are expected to be moderate or 
weaker for the next several days. Large NW swell over the
Guatemala-El Salvador offshore waters will continue through Fri 
night.

...REMAINDER OF THE AREA...

Please see the Special Features section above for details on a
significant swell event currently affecting the N portion of the
basin.

A cold front extends from 30N119W southwestward to 22N130W, 
where it transitions to a dissipating cold front to 11N139W. 
Isolated showers and thunderstorms are occurring north of 28N 
between 122W-125W. Winds are NW fresh to strong behind the front
north of 28N. In addition to the very large NW swell described 
above, NW swell of 8 ft or more are occurring north of a line 
from 20N140W to 27N120W. For the remainder of the waters, the NE
trades are fresh 07N-10N west of 137W and fresh to strong from 
05N-10N east of 100W with seas 8-10 ft. Elsewhere, the trades 
are moderate or weaker with seas 5-7 ft.

For the forecast, the cold front and an accompanying low center
will progress eastward with NW winds north of 25N east of 125W
dropping below fresh on Fri night. Likewise, the NE trades will
weaken to moderate across the waters by Sat. The large NW swell
will continue propagating southeastward while gradually
diminishing. 8 ft or greater seas with the swell will reach from
10N140W to 23W117W Fri night. Elsewhere, seas will be 6-8 ft.

$$
Landsea